"After the recent release of XDarwin, an XWindows port
for Mac OS X, and Mac Gimp, I finally had a means of comparative
analysis between The GIMP and Adobe's PhotoShop on my OS X machine.
Only a few months earlier, my wife had requested that her iBook,
with its dual-boot OS 9 and Linux PPC configuration, be limited to
only OS 9 as a means of conserving space.
Before installation of the open-source graphics software, I
admit my skepticism levels were extremely high, but after only an
hour of experimentation with the software, I came away extremely
impressed.
The GIMP not only employs a nearly identical feature set to
PhotoShop's, navigation is a cinch because both programs' floating
palettes are similar in nature. I was surprised to learn that I
could open native Photoshop files within The GIMP and retain a
file's layers as well as most of its layer filters. Alpha Channels,
layer masks, clipping paths, a slew of filters and almost all the
features I've known in PhotoShop were all available and at my
disposal."